On-wafer, in-line testing of output light power and spectrum of Photonic Integrated Circuits (PICs) can be challenging, especially for wide spectral band applications. One challenge relates to the fact that light is typically routed in the plane of the wafer through waveguides. It is difficult to measure or extract such light for testing purposes while PIC chips are still in wafer form, without diverting the light away from a surface of the wafer.